This invention relates to semiconductor memory array systems and more particularly to semiconductor array systems utilizing dynamic memory cells and dynamic control circuitry.
In computer and related apparatus there exists a need for relatively large information capacity semiconductor memories in which logic information can be temporarily stored and then retrieved within a useful period of time. These memories must be capable of relatively high speed operation and have relative low power dissipation. To economically meet such requirements it is necessary that the basic memory cell be a sufficiently simple structure which consumes relatively little power in order to permit a relatively large number to be fabricated and interconnected on a single monolithic integrated circuit chip. In addition, the control circuitry utilized should consume as little power as possible and should not require voltage pulse inputs which must be critically timed.
An integrated circuit manufactured by Intel, which is denoted as the 1103, employs a three-transistor dynamic memory cell that serves as the basic cell for a 1,024 bit random access memory, which is fabricated on a single monolithic integrated circuit chip. This circuit typically has an access time of from 150 to 300 nanoseconds, a cycle time of from 250 to 580 nanoseconds and power dissipation during the active cycle of from 300 to 500 milliwatts. While this circuit has many advantages, one of the major disadvantages is that it requires multiple complex input signals which must be critically synchronized. An improved version of the 1103, known as the 1103A, simplifies the timing requirement on the input signals, however, power consumption of the control circuitry is still relatively high and the timing requirements are still relatively strict.
It would be very desirable to today have a memory system which utilizes dynamic memory cells but in which the power dissipation of the associated control circuitry is significantly reduced and the timing requirements are significantly eased.